Published in Frontiers in Psychology, the study led by Dr. Jitka Lindová of Charles University in the Czech Republic and colleagues, asked university students to rate a series of faces on how attractive they were. Some photos shown were digitally manipulated in order to somewhat resemble the participant rating it. Others were manipulated to look less similar to the participants. Photo included those of the same and opposite sex.

The study found that singles rated the photos that looked less like them as being more attractive than those that resembled themselves. This result was found for both same and opposite sex faces. On the other hand, those who were in relationships found photos that looked similar to them as being more attractive.

"For the first time, we have observed how our partnership status affects who we find attractive," lead author Lindová said in a release. “Our interpretation is that attractiveness perception mechanisms that give us a preference for a genetically suitable partner may be suppressed during romantic relationships. This might be a relationship maintenance strategy to prevent us from finding alternatives to our own partner, or perhaps self-resemblance becomes more important in terms of the social support we expect and receive from relatives, which are known as kinship cues."

"A single person is often looking for someone exciting and sexually attractive,"Jean Fitzpatrick, a relationship therapist in Manhattan tells Bustle, "A person who already has a partner might instead, when viewing photos in this study, be imagining a different kind of connection — a familial one. From our earliest days we feel most connected to our family members, who look like us."

As this study notes, however, little research has been done to see how people’s perceptions change when they enter into relationships. However, from the few studies on this topic, here’s what we know so far:

1. How You Treat Others May Depend On Your Relationship Status

While one’s relationship status shouldn’t matter nor define you, one study finds we can’t help but judge people based on that fact. According to a 2013 study published in Psychological Science, your relationship status may influence how you treat others even in situations where relationship status shouldn’t matter. The study found that married couples treat their single friends like they’re lonely and wish “marital bliss” for them, at the same time singles pity their coupled up friends due to a perceived “loss of freedom.”

"We often become evangelists for our own lifestyles," the researchers wrote in the study. "When it comes to our relationship status, we are rarely content to simply say 'being single works for me' or 'being in a relationship suits my disposition.'"

2. Being In A Happy Relationship Can Change How Attractive Other People Are

The study, which was led by Rutgers University psychologist Shana Cole wanted to see whether people said they found other attractive individuals less attractive because they were in a relationship or if they actually saw them as less attractive. It was found that yes, people in relationships rated attractive individuals as less attractive than those who were single. However, that wasn’t the case for everyone — it only worked for people in happy relationships.

3. Being In A Relationship Changes You To Be More Like Your Partner Than Your Friends

Unsurprisingly, singles said their friends were among their most significant and influential relationships. However, once they entered into a romantic relationship, things changed. As it was found, teens who entered into relationships during the study had similar views on alcohol abuse with their partners than they did with their friends. Essentially their views shifted to match what their significant others thought.

4. Relationships Can Change Our Identities In A Way That May Determine Relationship Satisfaction

We know there comes a point where “me” becomes “we” in relationships. According to a 2014 study published in the Journal of Social and Personal Relationships, being in a close relationship may change one’s self-concept or identity. According to Psychology Today, relationships can change our identities in two ways. First, we can grow and expand. For instance, if you want to impress your partner with cooking skills that you currently lack, you may find yourself taking classes. At the same time, relationships can also shrink your sense of identity when you feel like something you used to love doing before gets lost when you start your relationship.

Researchers asked 55 adults in romantic relationships to complete surveys on their self-concept and relationship and found that people who felt their identities grew were more satisfied with their partner and relationship over time.